TOTAL TRANSURANICS ON ISLET MARY'S DAUGHTER
DOE/ERSP TECH NOTENO, 2.22

DATED: 14 August 1978

AUTHOR: J. Giacomini, DRI

Soil samples were taken from the surface only at four locations with two composites at each
location. Minimum, maximum and mean total transuranics from the two composites are listed
below. Since the island was not surveyed or staked, the locations were chosen by quartering the
island along the north, south, east and west compass directions from the approximate center of the
island. Samples were taken half way between the high tide line and the center of the island along
each major axis.
A ratio of total transuranics to americium was not computed for Mary's Daughter since the islet is

too small to do the in situ 2414m gammasurvey.

TRU
Loeation
North
East
South
West

Minimum
93.00
46.50
31.72
8.82

Maximum

Mean

138.83
55.59
47.70
10.38

115.92
51.05
39.71
10.60

DETERMINATION OF THE RATIO OF TOTAL TRANSURANICS TO
AMERICIUM IN SOIL FROM THE AOMON CRYPT
DOE/ERSP TECH NOTE NO. 2.23

DATED: 6 February 1979

AUTHOR: B. Friesen, DRI
Determination of one mean ratio for the Aomon Crypt was made using laboratory results from soil
core samples taken at 34 locations within the Crypt area. Samples were taken from 7 depth
intervals from 22 different holes, with emphasis on the area in the vicinity of the center monument.
Reference Tech Note 2.2-A for assumptions made in computing the mean ratio and associated
error. The range of values is from 4.64 to 7.98. The ratios are listed in Table B-2-8.
Three of the computed ratios were observed to be less than 5.0; when these three values are deleted
from the computations the mean ratio is 6.17 with standard deviation 0.64. The soil used to fill the
Crypt may have come from the Kickapoo area where the ratio was determined to be 6.16. Some soil
may also have been taken from the Yuma area where the ratio at the surface was 3.86 and for

subsurface was 5.3. The data suggest that the mixing of soils may have occurred, leading to the 3
values indicated by the asterisks in Table B-2-8.

There have not been enough samples processed

through the laboratory to substantiate the mixing hypothesis nor to suggest where the boundaries, if
any, would be. The difference in ratio between Kickapoo and Yuma soils is such that, with respect

to the 400 pCi/g criteria, 2414m values in the range from 64.9 to 75.5 would be of interest. All

samples indicated by IMP sereening to be greater than 25 pCi/g were gamma scanned in the

laboratory; only 3 of 71 such samples had 241 4m in the 65-76 pCi/g range.

The total transuranies to americium ratios were examined to see if there was a significant
difference either by depth or by lateral extent. No significant differences were found. Values for
total transuranies were found to increase with depth to the 16-18 ft. interval. Screening of 217

samples from below 18 ft., taken from 60 different drill holes, showed no sample with 2414m
activity greater than 8 pCi/g.

On the basis of the foregoing, a mean ratio of 6.17 with standard deviation 0.64 was used uniformly

throughout the Aomon Crypt to estimate TRU concentrations from the 2414m gammaactivities.
B-2-25

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